In real life it might be easier just to go with the direct international ticket and not to think about tricks

Sure in my case i will help travellers who travel from/ to Austria to get the best offer but at a point its insane to split the tickets.The CZK/ € exchange also cost. So 27 CZK cost more because it cost me X€ for exchange.

And you forgot something important! Split Ticket mean I an screwed up if something happen!!!

You're right. Splitting ticket is always risky, so I would suggest all to try it knowing the consequences. Had a bitter experience once and would never try again.

Getting from Lille to Brussels airport is relatively easy, since Lille is connected to Brussels by numerous high-speed trains (TGV, Thalys, EuroStar), so it actually takes <40 minutes to get to Brussels. Those trains arrive to the so-called Brussels-Midi train station, so you'll need to make a quick train change there for the local train that will take you (ride will be about 20 min.) directly to the airport. At the end your whole journey will be slightly more than an hour of time in total.

It's still too early to book train tickets for next September, but you can check app. timetables & fares on Belgium railways website - b-europe.com, while when the time will come you will be able to book your ticket there as well

Well, 1214 CZK for Vienna-Prague-Chomutov-Plzen-Rybnik is pretty decent price for the 1st class train ticket (especially taking into consideration that only Vienna-Prague cost 34 euro in this case), however with Rybnik-Linz-Vienna it seems latest reviews of phenq to be better to go with OeBB sparschiene ticket Summerau-Vienna (if bought in advance via OeBB website it costs only 14 euro + 10 euro for 1st class extra), while for the short cross-border 15 min. Rybnik-Summerau leg you can simply purchase a separate ticket for 2 euro

Thanks for recommending OeBB sparschiene ticket. It is quite cheaper. Will go for it and buy it in advance.

I'm just wondering should i be getting any eurail pass or any train pass if I'm doing travels milan to rome den rome back to milan .... and travel another day from milan to Zurich?

No, especially if you have more or less fixed date and time of the day, what will allow you in advance ticket purchase. In Italy there are plenty of various options to travel cheaply using trains, for instance with TrenItalia you can actually travel from Milan to Rome for as cheap as 9 euro (or 29 euro with daytime high-speed trains) + besides TrenItalia in Italy you have a chance to use private rail company (Italo), which also offers discounted tickets with in advance purchase. There is no such short term rail pass which will give you better fare then these discounted tickets, visit phenq review herebut even if there were in Italy besides actual rail pass for all the long-distance trains pass holders have to get seat reservation, which also costs money. So we advise you just to visit again TrenItalia website and Italo website, input Milan-Rome and Roma-Milan for the dates you want and see yourself how cheap you can travel

What would be the nearest city in Switzerland from Milan? Not really bothered which city in Switzerland we can see as long as we can save more time.

Well, nearest interesting (and relatively big) one is probably Lugano, you can then just make like a day trip there (it's only an hour away from Milan) and then come back to Milan to catch a cheap flight to the Netherlands. Or, alternatively, just continue from Lugano to one of the major Swiss airport (Geneva, Basel, Zurich), thus anyway end up traveling through the Switzerland by land (quite an experience itself, btw).

Also can I just book the tickets to Venice and Florence when I get there or do I need to purchase them in advance?

The thing here is that buying in advance allows you to get much cheaper (=discounted) tickets, while before departure you'll end up paying full standard fare price (=might be times higher than the cheapest discounted tickets). The only category of trains in Italy where you can disregard "early bird=cheap" rule is the regional trains, but those are somewhat slower compared to the high-speed one for which you can get good deals when buying in advance.

I could scratch off Florence from our IT and replace it with any country on the way to the remaining countries(Switzerland,Amsterdam, France) any suggestion on this?

Hmm... Florence is anyway on your route from Rome to Venice, so purely logistically it makes sense to stop there + it's a very beautiful city. But if we do speak about the alternative destination, what are your preferences? Old towns? Nature sightseeing (e.g. mountains, lakes)? Something else?